For ease of helping answer this question, a PDF file of pages 298 299 from Chapter 10 of the course textbook are posted along with these instructions. Read the PDF file, and identify the data entry control that is in place by defining the maximum number of characters of data for a field. Explain why, including reference to the news articles at the respective links above that show the absence of that control. 298 PART II CONTROL AND AUDIT OF ACCOUNTING INFORMATION SYSTEMS TABLE 10-1 Application Controls for Processing Integrity PROCESS STAGE THREATS/RISKS CONTROLS Input Data that is: Forms design, cancellation and Invalid storage of documents, autho . Unauthorized rization and segregation of Incomplete duties controls, visual scanning, Inaccurate data entry controls Processing Errors in output and stored data Data matching, hilo labels, batch totals, cross-footing and zero- balance tests, write protection mechanisms, database process ing integrity controls Output Use of inaccurate or incom Reviews and reconciliations, plete reports enayption and access controls, Unauthorized disclosure of parity checks, message sensitive Information acknowledgment techniques Los alteration, or disclosure of Information in transit check. An edit check that tests whether the characters feld we of the connected type umeric data in numerical w thack And check that verifies that the data in a field he appre rithmetic mit check An edt check that stanumerical wount og funde rangecheckAn edit check that whether a data with red up Dend wer units DATA ENTRY CONTROLS Source documents should be scanned for reasonableness and pro- priety before being entered into the system. However, this manual control must be supple- mented with automated data entry controls, such as the following: A field check determines whether the characters in a field are of the propertype. For ex- ample, a check on a field that is supposed to contain only numeric values, such as a U.S. zip code, would indicate an error if it contained alphabetic characters A sign check determines whether the data in a field have the appropriate arithmetic sign, For example, the quantity ordered field should never be negative A limit check tests a numerical amount against a fixed value. For example, the regular hours worked field in weekly payroll input must be less than or equal to 40 hours. Simi- ladly, the hourly wage field should be greater than or equal to the minimum wage. A range check tests whether a numerical amount falls between predetermined lower and upper limits. For example, a marketing promotion might be directed only to prospects with incomes between $50.000 and $99,999 An dit check that estuda completeness check for test An edit check that verifies that al data required have been entered. validity check - An edit test that compare the code or account number in transaction data with similar data in the master file to verify that the account exist reasonableness test - An edit check of the logical correctness of relationships among data Hem A size check ensures that the input data will fit into the assigned field. For example, the value 458,976,253 will not fit in an cight-digit field. As discussed in Chapter 8, size checks are especially important for applications that accept end-user input, providing a way to prevent buffer overflow vulnerabilities. A completeness check (or test) verifies that all required data items have been entered. For example, sales transaction records should not be accepted for processing unless they include the customer's shipping and billing addresses, A validity check compares the ID code or account number in transaction data with similar data in the master file to verify that the account exists. For example, if product number 65432 is entered on a sales order, the computer must verify that there is indeed a product 65432 in the inventory database. A reasonableness test determines the correctness of the logical relationship between two data items. For example, overtime hours should be zero for someone who has not worked the maximum number of regular hours in a pay period. ID codes (such as part numbers) can contain a check digit that is computed from the other digits. For example, the system could assign each new inventory item a nine-digit number, then calculate a tenth digit from the original nine and append that calculated number to the original nine to form a 10-digit part number. Data entry devices can then be programmed to perform check digit verification, which involves recalculating the check digit to identify data entry errors. Continuing our example, check digit verifica- tion could be used to verify accuracy of an inventory item number by using the first nine check digit- umbes such Inventory item number contain a check digit computed from the other digits. check digilt verification - Recal culating a check digit to verify that a data entry error has not been made 299 CHAPTER 10 PROCESSING INTEGRITY AND AVAILABILITY CONTROLS. digits to calculate what the tenth digit should be. If an error is made in entering any of the ten digits, the calculation made on the first nine digits will not match the tenth, or check digit. Note that check digit verification only tests whether an ID code in a transac- tion record could exist. A validity check is the only way to verify that the ID code really does exist The preceding data entry tests are used for both batch processing and online real-time pro cessing. Additional data input controls differ for the two processing methode ADDITIONAL BATCH PROCESSING DATA ENTRY CONTROLS Batch processing works more efficiently if the transactions are sorted so that the ac usually be totale counts affected are in the same sequence as records are stored in the master file, For example, accurate batch processing of sales transactions to update customer account bal. sequence check - An edit check that determine if a transaction ances requires that the sales transactions file first be sorted by customer account number. file is in the numerical or A sequence check tests whether a transaction file is in the proper numerical or alpha- alphabetical sequence betical sequence An error log that identifies data input errors (date, cause, problem) facilitates timely batch totals. The sum of numerical item for a batch of review and resubmission of transactions that cannot be processed. documents, calculated prior Batch totals calculate numeric values for a batch of input records. The following are to processing the batch, when the data are entered, and three commonly used batch totals: subsequently compared with 1. A financial total suma a ficld that contains monetary values, such as the total dollar computer-generated totale after each processing step to verify amount of all sales for a batch of sales transactions, that the data w processed 2. A hash total soms a nonfinancial numeric field, such as the total of the quantity correctly ordered field in a batch of sales transactions Financial total. A type of batch 3. A record count is the number of records in a batch. total that equals the sum of a field that contains monetary ADDITIONAL ONLINE DATA ENTRY CONTROLS value Prompting, in which the system requests each input data item and waits for an accept- hash toal-Atype of batch total generated by wming able response, ensures that all necessary data are entered (i... prompting is an online valus field that would not completeness check), Closed-loop verification checks the accuracy of input data by using it to retrieve and display other related information. For example, if a clerk enters an account number, the record count type of batch total that equals the number of system could retrieve and display the account name so that the clerk could verify that the records processedaraven correct account number had been entered A transaction log includes a detailed record of all transactions, including a unique trans action identifier, the date and time of entry, and who entered the transaction. If an online promoting An online data entry completeness check that file is damaged, the transaction log can be used to reconstruct the file. If a malfunction requests each required them of temporarily shuts down the system, the transaction log can be used to ensure that trans- input data and then waits for actions are not lost or entered twice. captable response before Testing the required PROCESSING CONTROLS les con An Controls are also needed to ensure that data is processed correctly. Important processing con- put validation method that trols include the following: date and into the system to retrieve and display the Data matching. In certain cases, two or more items of data must be matched before an Plated information so that the action can take place. For example, before paying a vendor, the system should verify that data typer averly the of the date Information on the vendor invoice matches information on both the purchase order and the receiving report how The File labels. File labels need to be checked to ensure that the correct and most current e and contain files are being updated. Both external labels that are readable by humans and internal labels that are writte in machine-readable form on the data recording media should be det used. Two important types of intemal labels are header and trailer records. The header label hing bon and aforma record is located at the beginning of each file and contains the file name, expiration date, and other identification data. The trailer record is located at the end of the file; in transaction files it contains the batch totals calculated during input. Programs should be designed to read the header record prior to processing, to ensure that the correct file is